Life Cycle Assessment with Carbon Footprint Analysis in Glulam Buildings: A Review

Abstract

This study provides a bibliometric analysis of life cycle assessments (LCAs) to explore the sustainability potential of mass timber buildings, focusing on glulam. The analysis highlights regional differences in carbon footprint performance within the ISO 14040 and EN 15978 frameworks. LCA results from representative countries across six continents show that wood buildings, compared to traditional materials, have a reduced carbon footprint. The geographical distribution of forest resources significantly influences the carbon footprint of glulam production. Europe and North America demonstrate optimal performance metrics (e.g., carbon sequestration), attributable to advanced technology and investment in long-term sustainable forest management. Our review research shows the lowest glulam carbon footprints (28–70% lower than traditional materials) due to clean energy and sustainable practices. In contrast, Asia and Africa exhibit systemic deficits, driven by resource scarcity, climatic stressors, and land-use pressures. South America and Oceania display transitional dynamics, with heterogeneous outcomes influenced by localized deforestation trends and conservation efficacy. Glulam buildings outperformed concrete and steel across 11–18 environmental categories, with carbon storage offsetting 30–47% of emissions and energy mixes cutting operational impacts by up to 67%. Circular strategies like recycling and prefabrication reduced end-of-life emissions by 12–29% and cut construction time and costs. Social benefits included job creation (e.g., 1 million in the EU) and improved well-being in wooden interiors. To further reduce carbon footprint disparities, this study emphasizes sustainable forest management, longer building lifespans, optimized energy mixes, shorter transport distances, advanced production technologies, and improved recycling systems. Additionally, the circular economy and social benefits of glulam buildings, such as reduced construction costs, value recovery, and job creation, are highlighted. In the future, prioritizing equitable partnerships and enhancing international exchanges of technical expertise will facilitate the adoption of sustainable practices in glulam buildings and advance decarbonization goals in the global building sector.

1. Introduction

The construction industry plays a pivotal role in global economic development, yet it remains one of the most significant drivers of environmental degradation. Responsible for approximately 40% of global CO₂ emissions and 35% of total energy consumption, the sector’s heavy reliance on carbon-intensive materials, such as concrete and steel, poses a critical challenge to climate sustainability [1]. As urbanization accelerates and infrastructure demands grow, the imperative for sustainable construction practices becomes increasingly urgent. Achieving the climate objectives outlined in the Paris Agreement—specifically, a 50% reduction in global carbon emissions from 1990 levels by 2050—necessitates a radical transformation within the sector. With a remaining global carbon budget of roughly 88 billion tons between 2015 and 2100 [2,3], the construction industry must rapidly pivot toward low-carbon materials, circular economy principles, and energy-efficient building strategies to align with planetary boundaries and foster long-term resilience.

One promising solution is mass timber, particularly glued laminated timber (glulam) and cross-laminated timber (CLT). Glulam is typically based on solid wood, which has inherent advantages in the ecological cycle. Figure 1 systematically illustrates the environmental impact processes of glued laminated timber buildings throughout their entire life cycle (A1–C4), encompassing raw material production (A1–A3), transportation and construction (A4–A5), operational maintenance (B1–B7), and end-of-life treatment (C1–C4). Through carbon sequestration by renewable timber, low-carbon manufacturing and construction practices, enhanced thermal performance reducing operational energy consumption, as well as waste recycling and biomass energy recovery reflect the sustainable potential of glulam buildings in carbon emission reduction, energy efficiency, and resource circularity [4]. By comparing the greenhouse gas (GHG) emissions of building life cycles in China, Finland, and the United States, the analysis found that regional differences in energy structure, material production, and building type significantly affected the carbon footprint of buildings. Finland and the United States had advantages in energy structure, environmental protection, and the application of wooden structures. As a result, their building carbon footprint is lower than China’s. Puettmann et al. [3] compared the global warming potential (GWP) of CLT buildings in three different regions of the United States, namely the Pacific Northwest, the Northeast, and the Southeast. The CLT buildings in the Pacific Northwest had the highest GHG emissions per unit of floor area.

Recent LCA studies have highlighted the sustainability performance of glulam buildings, demonstrating their ability to reduce carbon emissions during production, construction, operation, and end-of-life phases [6,7]. For example, Quintana-Gallardo et al. [8] used LCA to compare the environmental impact of wooden single-family model houses in different regions of Spain (Madrid, Valencia), Slovenia (Ljubljana, Portoroz), and Germany (Munich), where regional differences in the electricity mix also affected carbon emissions. Munich and Ljubljana had similar energy consumption, but carbon emissions varied depending on the electricity mix. Outside of Munich, the construction phase still accounted for more than 10% of carbon emissions. These regional disparities meant that the carbon footprint of glulam buildings was different in life cycle stages and difficult to compare, thus hindering the sustainable development of glulam buildings. However, the environmental impact of glulam structures varies significantly across regions due to differences in energy grids, manufacturing practices, and building designs [8,9]. These regional disparities pose challenges for establishing a unified framework for assessing the sustainability of glulam.

This systematic review evaluates the environmental performance of glulam buildings through a critical analysis of life cycle assessment (LCA) studies published over the past decade. Following international standards such as ISO 14040 and EN 15978 [10,11], this study specifically addresses three key research questions: (1) What is the sustainability potential of glulam buildings? (2) What is the carbon footprint profile of glulam across its entire life cycle? (3) How do regional factors influence sustainability outcomes?

This paper aims to address critical research gaps in the field, provide evidence-based policy and operational recommendations, promote sustainable construction practices, and advance decarbonization in the building sector. Figure 2 presents a four-stage workflow for conducting a bibliometric analysis. This study used the Web Of Science Database, and the initial search yielded 673 publications, including journal articles, conference proceedings, and books. These publications had been rigorously screened to include only peer-reviewed literature from 2014 to 2024 that complied with ISO 14040/EN 15978 standards after removing duplicates and irrelevant studies (e.g., non-glulam building applications), as well as consolidating synonyms. Following this, the Visualization of Similarities Viewer (VOS-viewer) generated keyword co-occurrence networks and regional collaboration mapping to identify research hotspots through publication metrics, citation analysis, and keyword clustering, ultimately analyzing global research trends in the life cycle assessment (LCA) of glulam buildings, with particular emphasis on carbon footprint characteristics. The methodology used for this study followed that of previous research [5].

2. Life Cycle Assessment

In principle, the sustainability of a building is evaluated by quantifying the economic, social, and environmental impacts associated with it through its entire life cycle [12]. LCA is an established tool that is used for measuring the environmental impacts associated with all stages of a glulam building’s life cycle. The International Organization for Standardization (ISO 14040) defines the standard LCA framework, which consists of four main stages [10] as shown in Figure 3, as follows: the life cycle of a building starts with the extraction, production, and transportation of raw materials and extends to construction, operation, and maintenance, up until demolition and waste management at the end of its service life [13]. In the context of buildings, the European Standard EN 15978 divides the life cycle into four distinct phases [11].

Table 1. Life cycle stages and processes.

Module	Phase	Stage	Processes
A1–3	Production	A1	Raw Material
		A2	Transport
		A3	Manufacturing in Factory
A4–5	Construction	A4	Transport
		A5	Installation and Erected Process
B1–7	Service Life	B1	Use
		B2	Maintenance
		B3	Repair
		B4	Replacement
		B5	Refurbishment
		B6	Operation Energy
		B7	Use Operation Water Use
C1–4	End-of-Life	C1	Demolition
		C2	Transport
		C3	Waste Idleness
		C4	Waste Management
D	Potential Benefits and Loads	D1	Other Environmental Impacts

summarizes these phases: material production and construction (Modules A1–5), service life (Modules B1–7), end-of-life (Modules C1–4), and potential benefits and loads beyond the system boundary (Module D), where additional environmental impacts may occur.

An increasingly popular tool for bibliometric analysis is the VOS-viewer. It efficiently visualizes similarity networks, clustering, and mapping of research data, supporting applications such as keyword co-occurrence analysis, co-citation analysis, co-authorship analyses, bibliographic coupling analyses, and others [14]. As already mentioned, data were extracted from Web Of Science, considering glulam and CLT as wood-based materials used in the construction sector, keywords such as Wood/Timber, Building/Construction, and LCA were used in the initial search. The search results were sorted by relevance, and finally, a total of 563 references were obtained. We imported the references in a .csv (Microsoft Excel) file format using the bibliometric tool VOS-viewer for the analysis of research trends, keyword co-occurrence maps, author affiliations, and LCA research results by region.

Keywords are an essential component of any research article; they convey the basic information about the content and direction of the literature. According to the preferred settings of the VOS-viewer, the keyword occurrences were filtered more than 5 times to highlight the importance of the research, as shown in Figure 4, and the initial search of author keywords resulted in 82 terms. Concerning the general practices and literature conventions in the field of LCA research. Synonyms for terms like Wood and Timber, Building and Construction, LCA and CLT were categorized and merged. Finally, 54 research keywords were identified, as shown in

Table 2. Keyword analysis.

Keywords	Occurrences	Total Link Strength
Life Cycle Assessment (LCA)	359	522
Life cycle cost	17	24
Dynamic LCA	12	23
Simapro	6	13
Comparative LCA	5	9
Cradle-to-cradle	5	15
Wood	37	84
Wood buildings	27	47
CLT	33	77
Mass timber	11	33
Wood products	10	20
Bio-based materials	7	14
Natural materials	5	5
Environmental product declaration	7	13
Material substitution	6	14
Timber structures	5	9
Concrete	9	22
Buildings	48	105
Building materials	21	48
Green building	5	11
Built environment	5	13
Residential building	11	21
Building information modeling	5	7
Building design	8	24
Building envelope	7	12
Embodied carbon	32	76
Biogenic carbon	28	78
Carbon footprint	19	37
Carbon storage	23	53
Carbon emission	11	16
Sustainability	38	80
Sustainable construction	12	15
Sustainability assessment	6	15
Environmental impact	50	96
Industrial ecology	6	15
Global warming	35	85
Climate change	20	53
Greenhouse gas emissions	22	51
Climate change mitigation	8	19
Embodied energy	19	38
Energy consumption	11	21
Energy efficiency	9	19
Primary energy	7	16
Energy	5	8
Land use	7	15
Circular economy	21	39
Bioeconomy	6	8
Construction and demolition waste	6	12
Recycling	6	10
Circularity	5	13
Reuse	5	12
End-of-life	5	8
Transport	5	9
Allocation	5	13

. As a core term related to environment and sustainability, LCA appeared 359 times with a total link strength of 522, making it an extremely critical concept. Meanwhile, Simapro, a world-leading LCA software tool, appeared six times with a total strength of 13. Sustainability appeared 38 times with a total strength of 80 and served as a crucial link connecting various specific LCA research directions. Environmental impact appeared 50 times with a strength of 96, highlighting the focus on the impacts of various activities and materials on the environment. Combined with methods like LCA, it provided a basis for sustainable development decision-making. Global warming, Climate change, and Greenhouse gas emissions appeared 35 times, 20 times, and 22 times, respectively, reflecting the research community’s strong focus on global climate issues. Related studies often revolved around how to mitigate climate change and its associated impacts through various means.

• Keywords such as Buildings, Wood buildings, and Residential buildings indicate that the research spans a range of building types, from general construction to specific wooden and residential structures. The term Building materials appears 21 times, with particular focus on wood-based materials like Timber structures, GLT, CLT, and Mass timber. This reflects growing interest in their characteristics, applications, and environmental impacts within sustainable construction.
• Related terms such as Building design, Building envelope, and Building information modeling suggest a broader research scope, encompassing not just materials but also design strategies, enclosure systems, and digital tools that enhance building performance and sustainability.
• Carbon-related keywords, including Embodied carbon, Biogenic carbon, Carbon footprint, and Carbon storage, appear frequently, signaling a strong focus on measuring carbon emissions, content, and storage in wooden buildings. These metrics are critical in assessing sustainability, especially in the context of climate change.
• Energy-related terms such as Embodied energy, Energy consumption, Energy efficiency, and Primary energy reveal a significant emphasis on energy use and efficiency throughout a building’s life cycle. This aligns with the Sustainable Development Goals to reduce energy demand and improve utilization.
• Terms like Circular economy, Recycling, Reuse, Circularity, and End-of-life underscore the importance of circular design principles. The research highlights strategies for managing materials at the end of their life cycle and creating systems that minimize resource waste and environmental impact.

We selected studies that covered a wide range of locations globally, involving 63 countries. As shown in Figure 5, the bar and line chart illustrates the number of publications (bars, left y-axis) and citations (line, right y-axis) related to research on a specific topic across six global regions: Europe, North America, Asia, Oceania, South America, and Africa. The international distribution included 14 countries in Asia with 111 publications and 2454 citations; 35 countries in Europe with 276 publications and 6985 citations; 2 countries in Africa with 4 publications and 25 citations; 3 countries in North America with 113 publications and 3030 citations; 7 countries in South America with 25 publications and 603 citations; and 2 countries in Oceania with 34 publications and 613 citations. The geographical attribution analysis of publications is based on “countries of authorship” to reflect the main contributing regions of the research.

In Figure 6, different colors represent the clusters, with node size indicating the contribution level of research and the thickness of the connecting lines showing the relationships between them. Europe has the highest number of citations and publications, indicating that European research outcomes are widely recognized and influential internationally. The dense connections among European countries, such as Germany, Belgium, Italy, and Switzerland, positioned Europe at the network’s core. This reflected strong regional synergy in scientific collaboration. Europe also served as a key partner in many research projects. North America also had high citation and publication numbers driven by the influence of research from the United States and Canada. Asia had a considerable citation and publication number, demonstrating the growing impact of its research outputs. Oceania, South America, and Africa had relatively lower citation and publication numbers. Countries such as China, Japan, and Australia showed connections to multiple countries, including Canada, Australia, and the United Kingdom, indicating their active roles in international scientific collaboration. Chile’s connections with countries like China and the United States highlighted cross-regional research cooperation. Such collaborations facilitated the exchange of knowledge and technology and fostered innovation.

3. Multi-Aspect Impacts

In this section, we will review the environmental, economic, and social impacts.

3.1. Environmental Aspect

Life cycle assessment (LCA) aims to quantify environmental impacts, minimize resource consumption, and reduce pollution.

Table 3. Life cycle stages of glulam buildings.

Ref.	Location	Building Profile	Contrasting Material	Key Findings
[16]	Finland	Five-story apartment, 7250 m2, CLT, 50-year lifespan	Wood concrete	28% lower emissions (A1–A3), 55% lower emissions (A4), highest CO2eq 44,627 kg, most advantageous timber, 47% in the eutrophication impact category
[17]	USA	Twelve-story mixed-use apartment/office, 8360 m2, 1782 m3 CLT, 557 m3 glulam	Concrete and rebar	18%, 1%, and 47% reduction in the impact categories of global warming, ozone depletion, and eutrophication, respectively (A1–A5)
[18]	Uruguay	One-floor single-family house, 63 m2, CLT, 60-year lifespan	Concrete masonry structure	Glulam had low median values in impact categories such as GWP, AP, FWE, HT, and ODP, but was higher in use phase (B2–B4)
[19]	Malaysia	One-floor residential, 142.88 m2, CLT beams, steel-plate walls/roofs, 50-year lifespan	Light steel frame, concrete, brick	Lower emissions in all environmental categories, namely, GWP, HT, FDP, OLD, TA
[20]	China	Seven-story CLT structure, 2799.3 m2, 50-year lifespan	Concrete	30% reduction in energy use, 40% reduction in CO2 emissions
[21]	Japan	Two-floor research building, 1424.23 m2, CLT	Concrete foundation	CLT 17% of total impact, stored carbon 32% of emissions, biomass-derived electricity was also reduced on acidification by 5%, and photochemical oxidation was reduced by 7%
[22]	USA	Twelve-story mixed-use, 8360 m2, glulam columns/beams, CLT floors/walls, 60-year lifespan	Concrete and rebar	70% lower emissions than RC (excluding B6)
[15]	Norway	Eight-story CLT study, 3973 m2 heated, 695 m2 basement, 100-year lifespan	Five-story concrete, 2449 m2 heated	Among the 18 environmental impact indicator categories, CLT buildings scored the lowest in 11 impact categories, especially with a CLT of 49.7% lower for GWP
[23]	Italy	1 m2 CLT external wall, primary school classroom, 50-year lifespan	\	for 14 impact categories, the use phase has the highest environmental impact, in particular, ozone depletion, freshwater cutrophication, and ecotoxicity for aquatic freshwater, followed by the production, end-of-life, raw material acquisition, and construction phases
[24]	China	4–17 stories, 4900–26,500 m2, 50-year lifespan	RC	13% lower GWP than RC (excluding B3–B5)
[25]	Australia	10 stories, no basement, 1558 m2, 75-year lifespan	RC	40% reduction in GHG emissions, FW about 20 times lower, and PENRT reaching a negative value
[26]	Chile	Five-story midrise social housing, CLT, 1405 m2	Concrete (same design)	42% lower embodied emissions, biogenic carbon storage 447 tons CO2eq/m2
[27]	Germany	2–4-story office/admin buildings, 292–5445 m2, agricultural buildings 906–2555 m2, 50-year lifespan	Steel, concrete, brick	Office/admin emissions reduced by 6–48%, agricultural by 5–37%, non-agricultural by 14–44%
[28]	Sweden	Eight-story, 3374 m2, CLT, 50-year lifespan	\	203.4 kg CO2eq/m2 (material production), reduction up to 43% with engineering solutions

shows the environmental impacts during the building life cycle of representative countries from six continents that use locally produced glulam in buildings, and carbon emissions were compared using the conversion factor of emissions per m². The studies followed EN 15978:2011 life cycle assessment stages and corresponding modules. The buildings ranged from low to high rises, with floor areas ranging from 63 to 13,488 m². Building types include residential apartments, commercial, and mixed-use. The samples included four buildings from Europe, three from North America, four from Asia, two from South America, and one building from Oceania. Data from Africa were not available at the time of study. Overall, the results of LCA studies indicated that, compared to traditional construction solutions, the impact on most environmental categories is reduced when using wood material, but we cannot conclude if it has the best environmental performance because the impact categories where the traditional construction has the lowest impact scores might be the most important. Furthermore, the environmental impact of glulam is mainly in the reduction in GHG emissions, which is in line with previous studies [15]. The quality of data used in the LCA studies conducted on glulam buildings has been an ongoing challenge. This is perhaps unsurprising as glulam buildings are constructed using relatively new materials produced by a limited number of manufacturers. Moreover, existing glulam buildings have not yet reached the end of their service lives, which thus leads to approximations or significant limitations while assessing the life cycle carbon footprint of these buildings.

During the raw material processing stage, the primary material for glulam is wood. Wood absorbs carbon dioxide during its growth, contributing to mitigating climate change [29]. The energy required for glulam production is primarily used in processes such as cutting, drying, and gluing. A significant portion of this energy can be supplied by electricity or biomass [30]. Compared to the high-temperature calcination in concrete production and the complex smelting processes in steel production, the carbon emissions from glulam production are significantly reduced [31,32]. However, while high-performance adhesives ensure the strength and durability of glulam, the production of adhesives itself also generates carbon emissions. Missiatto Gavioli et al. [33] found that the use of bio-based adhesives in production process produced significantly lower carbon emissions than traditional petroleum-based adhesives, but still faces significant technical and cost limitations in development. For instance, bio-based adhesives (e.g., soy protein) can achieve 70–85% of the dry strength of traditional phenolic resin (PF), but their wet strength drops significantly (only 40–50%). Under hygrothermal cycling tests, the adhesive layer exhibits strength degradation, making it difficult to comply with the ISO 20152-1:2010 standard [34]. Due to higher extraction costs of raw materials (e.g., tannins and high-purity proteins) and increased production expenses from modification processes (e.g., enzymatic treatment and nanofiller incorporation), certain bio-adhesives (e.g., starch- or lignin-based formulations) require adjustments to hot-pressing parameters and extended curing times, which negatively impact production efficiency [35]. Currently, bio-based adhesives have only achieved commercial viability in limited non-structural applications. Large-scale implementation will require breakthroughs in reducing raw material production costs and demonstrating long-term durability performance.

During the transportation and construction stage, the high strength-to-weight ratio of glulam could reduce energy consumption. Transportation distance has a significant impact on the building’s environmental footprint. The study [22] found that when CLT was sourced from Europe, the global warming potential of timber buildings was higher than that of concrete buildings. During the construction process, a study by Jolly et al. [25] indicated that concrete building materials, being heavier than glulam, resulted in higher CO₂ emissions from crane operations. The prefabrication and modular assembly of glulam reduce the time required in temporary facilities on-site, thereby lowering energy consumption and associated emissions. Dodoo et al. [28] reduced the number of connectors by optimizing the connection system, improving assembly efficiency, and consequently, reducing the material production carbon footprint of CLT components by 1.1%.

During the service life stage, glulam buildings exhibit excellent thermal insulation properties, which help reduce the heating and cooling demands during operation, thereby lowering energy consumption and GHG emissions, especially in colder regions [20]. Felmer et al. found that the greenhouse gas emissions during the operation phase of passive CLT building designs are lower than those of traditional concrete buildings [26]. However, buildings in the operation phase may experience increased environmental impact due to maintenance requirements, such as the extensive use of paints in wood maintenance. This introduces challenges in predicting the end-of-life outcomes and results beyond the system boundaries [18,36]. The release of biogenic carbon at the end of a glulam building’s life increases the environmental impact [21]. However, extending the building’s lifespan could help achieve long-term carbon reduction benefits. At the end of their lifespan, the wooden components of a building could be dismantled and recycled. The research of [37] pointed out that reusing or recycling wood at the end of a building’s life can further improve its life cycle performance and reduce the demand for new timber extraction.

3.2. Economic Aspect

The economic benefits of glulam are mainly reflected in the circular economy. As shown in Figure 7, the circular economy starts from the awareness of resource limitations, unlike the traditional linear economic model, which is based on the cradle-to-cradle concept [12]. This involves production, distribution, and operation, followed by the recycling and reuse of raw materials, with the entire process being sustainable and interconnected. This approach reduces or eliminates waste and maximizes the value of resource usage.

Table 4. Study on circular economy performance of glulam buildings in different countries.

Region	Research Focus	Findings
China [38]	Carbon transfer from forests through industrial processing to end-use wood products	Annual net carbon sink of 14.9 Tg C per year, cumulative absorption of 893 Tg C, with 76% stored in furniture products. The carbon pool of HWPs could absorb up to 2979 ± 806 Tg C.
Japan [39]	Environmental impact and emission reductions of wood consumption from 1970–2013 using LCA	Increased wood use for construction, furniture, and energy production could reduce environmental impacts by CNY 357 billion in 2050.
South Korea [40]	Material circularity and environmental impact of timber hybrid public building	Environmental impact reductions of −13.5%, −11.5%, and −5.0% based on different structural applications. BCI improved from 0.26 to 0.31, 0.29, and 0.25.
Malaysia [19]	Application potential of wood in local construction	Using wood in steel and concrete construction could save 36–45% in production, labor, transportation, and machinery costs.
Germany [41]	Recycling technology for recovered solid wood into GLT products	Recycling into GLT resulted in 29% lower environmental impact and 32% lower costs than incineration.
Slovakia [42]	Benefits of prefabricated panel wood construction (PWC)	Construction time 48% shorter, cost 15% lower, and transportation cost 57% lower than brick and stone buildings.
European Countries [43]	Assessment of construction wood use intensity	Cyprus and Malta had the least use (0.01 ratio), Estonia and Romania had the highest (0.32 ratio).
Italy [44]	Environmental and market performance of wood supply chains	OSB manufacturing is a better alternative for energy use of wood chips; recycling provided better end-of-life treatment.
Norway [45]	Feasibility and sustainability of CLT in industrial buildings	CLT elements could achieve 3.3% total energy cost savings.
USA [46]	Comparison of steel frame and wood alternative for a four-story office building	75% of CLT and 95% of glulam could be reused; remaining converted to particleboard.
Canada [47]	Feasibility of converting construction and demolition wood waste into biofuels	Biofuel production was economically feasible when considering GHG emission reductions.
Brazil [48]	Circular economy strategy using recycled wood chips	Recycling wood waste into bio-concrete provided a carbon sink and contributed to low-carbon construction.
Australia [49]	Comparison of GHG emissions and life cycle cost of CLT vs. reinforced concrete buildings	CLT buildings had lower initial costs (8–10% savings), 30% less construction time, and lower labor, demolition, and recycling costs. However, maintenance was 13–16% more expensive than RC.
South Africa [50]	Log resource availability and global warming impact of wood-based residential buildings	High self-sufficiency in forestry products; valuable sawn timber market; provided sustainable forest management practices.

shows the circular economy performance of glulam buildings in different regions.

In the raw material processing stage, a study from China showed that between 1961 and 2020, the carbon sink of end-user furniture products produced 14.9 Tg C per year, accumulating to a total of 893 Tg C with 76% stored in the furniture products themselves [38]. Another study from Japan predicted that by 2050, the increased use of wood in construction, structures, furniture materials, and energy production could reduce costs by CNY 357 billion through carbon storage, material substitution, and fuel substitution [39]. This highlighted the value of carbon storage. Furthermore, in South Africa, which has a high self-sufficiency rate in forestry products, sustainable management ensured the supply of forest resources [50]. A study from Slovakia analyzed prefabricated timber frame buildings during the transportation and construction stage. It was found that, compared to brick and stone buildings, construction time was reduced by 48%, construction cost was lowered by 15%, and transportation cost was lowered by 57%. Noise, dust, and waste emissions were also reduced [42]. Another study from Malaysia showed that the use of wood in steel–concrete buildings could save costs by 36–45% [19].

In the service life stage, glulam buildings play a significant role in energy conservation and emission reduction, particularly in cold-climate regions. For example, Svortevik et al. [45] studied the use of CLT in industrial buildings for Nordic climates and found a potential 3.3% in total energy savings. In Australia, glulam residential projects proved that their excellent insulation properties could reduce energy consumption during service. Compared to conventional brick–concrete houses, winter heating costs and summer cooling costs were reduced by approximately 25%. Although maintenance costs are 13–16% higher than reinforced concrete buildings, the overall long-term operational cost advantage was evident [49]. At the end of its lifespan, wood has a higher building circularity indicator (BCI) compared to steel–concrete structures [40]. A study in the United States compared traditional steel-frame structures and large-scale wood alternatives for a four-story office building. It was pointed out that 75% of CLT and 95% of glulam could be directly reused at the end of their life, with the remainder converted to particleboard [46]. Goldaraz-Salamero et al. [44] explored the environmental and market performance of two timber supply chains in northern Italy. It was found that oriented strand board (OSB) is the most valuable alternative produced by recycling wood. Another study from Canada explored the economic feasibility of converting wood waste into biofuels [47]. Furthermore, new recycling technologies in Germany have transformed recycled solid wood into glulam products, reducing environmental impact by 29% and costs by 32% compared to incineration-based wood recycling. This demonstrated both environmental and economic benefits [41]. A study in Brazil highlighted the potential for converting recycled wood chips into bio-concrete to act as a carbon sink [48]. In summary, the diverse experiments from different countries in all life cycle phases of glulam buildings have accumulated valuable experience, contributing to the development of a circular economy.

3.3. Social Aspect

Social sustainability can be interpreted as the protection and enhancement of human–social capital, which is the guarantee of well-being (safety, health, education, etc.) equally distributed among the population [12].

Table 5. Social sustainability metrics in glulam buildings.

Community Well-Being	Cultural Significance	Workforce and Job Creation	Equity and Accessibility
Contributions of glulam buildings to community health and safety, improvement in living conditions	role of glulam in preserving architectural heritage and supporting culturally appropriate designs	opportunities in forestry, manufacturing, and construction sectors tied to glulam supply chains	addressing housing affordability, inclusive design for vulnerable populations, and fair labor practices

summarizes indicators of social sustainability in glulam construction.

Community well-being is commonly evaluated through a combination of subjective surveys and objective quantitative measures. The study on building preference reported attributes of wood products that were particularly appreciated [51,52,53]. The criteria include a set of measurable physical parameters, called indoor environmental factors, evaluating thermal comfort, visual comfort, indoor air quality, and acoustical quality. The criteria corresponding to the connection with human physiology were described [54], as shown in

Table 6. The criteria in terms of measurable physical parameters, related to human physiology.

	Thermal Comfort	Visual Comfort	Acoustic Comfort	Indoor Air Quality
Parameter	PMV/PPD or operative temperature; Humidity; Air velocity; Vertical air temperature differences; Radiant temperature asymmetry; Surface temperature of the floor	Requirements for lighting and day lighting provision; View out; Exposure to sunlight; Illuminance; Luminance; Light uniformity; Glare; Color (color rendering, light source color)	Sound level difference; Sound insulation; Sound absorption; Noise level(s) Frequency	Pollutant concentrations (such as VOCs, CO2), ventilation parameters, airflow patterns and pressure relationships
Human Physiology	Skin heat receptors; Core body temperature regulation system	Visual system	Auditory system	Respiratory and inhalation systems, olfactory systems
Influence Factors	Mild temperature; Humidity regulation	The fit of biophilic design	Sound absorption characteristics	Woody aroma, antibacterial performance, and low-carbon environmental sustainability

. In this regard, it is noteworthy that several studies have explored the connection between the use of wood and the physical and mental well-being of occupants. Wood in buildings reminds occupants of contact with nature. For example, wooden interiors in offices conveyed a sense of innovation, vitality, and comfort, which could enhance employee well-being and boost productivity. Visible wood grain reduces stress hormone secretion by 15% [55]. Another study suggested that the use of wood material in hospitals had a positive impact on patient healing, reducing hospital stays [56]. In earthquake-prone countries like Japan or cold Nordic regions, the use of glulam in buildings significantly enhanced residential safety and comfort [57,58,59]. Additionally, in remote forested areas like Sardinia and parts of South Africa, the supply chain of timber products had created employment opportunities and stimulated the local economy [12,50]. In the EU, the timber industry contributed significantly to their GDP. Gross capital reached EUR 122 billion and added value reached EUR 31.2 billion while providing employment to over 1 million people in 184,000 companies, from which most are small or medium-sized enterprises (SMEs) [60]. Glulam also presented a viable alternative to construction and renovations, particularly for the revamping of old buildings and the restoration of historic buildings. This included preserving cultural heritage by adding new floors to revamp old residential buildings in urban areas [61,62,63].

4. Carbon Footprint Analysis

Many countries worldwide are actively addressing the climate crisis and broader environmental issues. Glulam buildings contribute to these efforts by offering a sustainable construction option that supports carbon reduction goals. However, their environmental impact can vary by region due to different materials, construction practices, and energy sources.

4.1. Raw Material Processing Stage

Glulam is primarily manufactured from solid wood. Its production involves pre-treatment processes such as cutting, grading, and drying, followed by pressure bonding with high-performance adhesives. This stage mainly includes logging and transporting raw materials to processing facilities. As illustrated in Figure 8, the geographical distribution of forest resources significantly influences the carbon footprint of glulam production [64]. This is critical not only for offsetting emissions generated during harvesting and processing but also for enhancing the material’s carbon storage potential.

Europe has a well-developed forest management system that promotes sustainability through forest certification, carbon trading mechanisms, and policy-driven initiatives. Nordic countries such as Sweden and Finland are at the forefront of glulam construction, pioneering its use as a means of enhancing carbon sequestration [65,66,67]. North America’s carbon storage potential is strongly linked to its extensive forest resources, with Canada alone accounting for 347 million hectares, approximately 9% of the world’s total forest area. Canada has long been a leading producer of harvested wood products (HWP). Through the implementation of sustainable harvesting and renewal strategies, carbon emissions associated with timber harvesting can be significantly reduced [68]. Chen et al. [69] investigated forest carbon stocks under a baseline harvesting scenario across four forest management units. Their study found that carbon stocks initially declined from 1.359 megatons of carbon (MtCO₂e) to 1.353 MtCO₂e over 20 years, but subsequently rose to 1.426 MtCO₂e after 80 years, where they stabilized. These findings suggest that, in the long term, sustainable forest harvesting for wood production offers greater benefits for greenhouse gas mitigation compared to forest conservation alone.

Tropical rainforest ecosystems in South America and South Africa possess exceptionally high-carbon-storage capacity. Glulam processing facilities in these regions are often strategically located near forest resources, enabling the sourcing of timber within short transport distances, thereby reducing carbon emissions associated with transportation. Strict protection of tropical rainforests helps minimize disturbance to natural ecosystems and extends the duration of carbon sequestration [50,70]. Asia’s carbon storage capacity varies significantly due to differences in forest types and regional distribution. High-carbon-storage areas are primarily concentrated in East Asia, such as the coniferous forests of Northeast China and the Russian Far East, and in Southeast Asia, including the tropical rainforests of Indonesia and Malaysia. Although Southeast Asia’s rainforests possess high-carbon-storage potential, they face challenges from illegal logging, which results in carbon removal from the system through wood products, but eventual end-of-life decomposition releases carbon back into the atmosphere, compromising long-term climate mitigation benefits. Consequently, sustainable forest management must integrate both responsible harvesting practices and extended carbon storage in durable products. Through the utilization of plantation forests, carbon sequestration can be achieved in the short to medium term; however, this approach must be carefully balanced with the preservation of natural forests to ensure long-term climate mitigation benefits [71]. In recent years, China has actively promoted glulam construction technologies by using fast-growing wood, which not only reduces carbon emissions associated with traditional building materials but also contributes to sustainable forest management. In Oceania, forest resources are relatively concentrated. Australia and New Zealand have established large-scale plantations of fast-growing species such as Radiata pine, providing a steady supply of raw materials for glulam production [72,73]. Moreover, the adoption of advanced production and processing technologies in these countries enhances wood utilization efficiency and reduces emissions caused by outdated equipment and energy waste. For example, glulam plants in Germany have begun incorporating clean energy technologies, such as biomass and solar power, into their production processes to further reduce their carbon footprint [74]. In contrast, many countries in Asia and Africa continue to rely heavily on coal and oil due to slower progress in energy transition [75].

4.2. Transport and Construction Stage

The transportation and construction phase encompasses the delivery of finished glulam products to construction sites, the installation of components, and the operation of related machinery and equipment. Transportation distance, shaped by the geographical distribution of material suppliers, plays a significant role in the overall carbon footprint. Atnoorkar et al. [76] examined four transportation scenarios ranging from 1029 to 6953 km in the United States and found that longer distances could contribute up to 923 MJ/m² (20%) of energy consumption in glulam buildings. When higher-density wood species were used, this contribution rose to 1246 MJ/m² (24%), largely due to increased fossil fuel use. Similarly, Chen et al. [77] revealed that transporting glulam from Southeastern China to a construction site over 2000 km away resulted in a global warming potential (GWP) of 252–270 kgCO₂/m², which exceeded that of equivalent reinforced concrete (RC) buildings (245 kgCO₂/m²) when road transport was used.

Table 7. Transport modes, turnover, and carbon emission factors.

Mode of Transport	Turnover	Carbon Emission Factor
Aviation	1293.25 t·km	899.48 g/(t·km)
Road Freight	59,636.39 t·km	97.60 g/(t·km)
Railway	41,539.10 t·km	11.3 g/(t·km)
Water Transport	104,003.15 t·km	8.65 g/(t·km)

illustrates the carbon emission factors of various transportation modes. Aviation has the highest emissions at nearly 900 g/(t·km), approximately 9 times that of road transport, 79 times that of rail, and 104 times that of water transport. Road transport, the second most carbon-intensive mode, emits roughly 9 times more than rail and 12 times more than water, making it a key target for transport-related carbon reduction strategies [78]. Calculating carbon emissions from on-site construction, referred to as Embodied Construction Emission Assessment (ECEA), is complex. It includes direct energy use, emissions from machinery and equipment, indirect emissions from transporting construction tools, and the carbon impact of off-site personnel activities [79]. However, the adoption of advanced prefabrication and assembly technologies in some developed countries has helped mitigate these emissions. Techniques such as intelligent prefabrication and 3D printing can reduce on-site construction time, minimize machinery use, and enhance overall efficiency [80,81,82].

4.3. Service Life Stage

The service life stage encompasses the building’s energy consumption and maintenance activities, both of which are significantly influenced by regional climatic conditions. As illustrated in Figure 9, heating and cooling systems represent the dominant sources of energy use, contributing approximately 80% to 90% of carbon emissions during the operational phase [83,84,85].

Carbon emissions tend to be higher in equatorial regions and across parts of Asia, particularly in non-residential buildings. In contrast, residential buildings in China exhibit lower emissions compared to other Asian countries. Regions such as Australia, the European Union, and snow-covered areas demonstrate better performance in carbon reduction, often due to climate-adapted building strategies and cleaner energy sources. Numerous studies conducted in countries including China [86], Denmark [87], Italy [88], Sweden [89], the United States [3], and Australia [90] have affirmed the carbon reduction benefits of glulam, particularly in low-energy buildings. These benefits are most evident in colder climates, where heating systems account for a significant portion of operational emissions. The energy mix plays a critical role in shaping a building’s carbon footprint. Zhang et al. compared several heating systems for high-rise residential buildings in cold regions of China, revealing a progressive decrease in emissions from coal-fired boilers to solar-assisted heat pumps [91]. Similarly, studies in Spain and Colombia found that replacing high-carbon electricity with low-carbon alternatives reduced building energy consumption by 9% to 67% [92]. Optimizing the energy mix has proven to be a key strategy for carbon reduction. In Sweden, research by Växjö et al. demonstrated that wooden buildings utilizing district heating in combination with biomass-based integrated gasification combined cycle (BIGCC) systems, or heat pumps paired with BIGCC, could achieve net-negative carbon emissions [93]. Likewise, a study by Korsavi et al. on a UK campus building showed that integrating photovoltaic systems reduced energy consumption by 30% [94].

However, operational emissions are not limited to energy use; buildings also undergo maintenance and replacement over time. Glulam buildings, particularly in high-humidity tropical and oceanic climates, are susceptible to wood decay, mold, and related deterioration [7]. Regular inspections and proactive maintenance can help minimize the long-term carbon footprint associated with these issues. Most LCA studies assume a service life of 50 to 60 years for glulam structures, which aligns with the commonly accepted structural lifespan of 40 to 75 years [95]. To improve the accuracy of carbon footprint assessments related to maintenance and repair, the development of robust service life prediction models for glulam buildings is urgently needed.

4.4. End-of-Life Stage

The end-of-life phase of glulam buildings encompasses activities such as demolition, waste transportation, and final disposal. Timber structures, in particular, offer significant carbon reduction potential through the recycling and reuse of materials, as well as energy recovery processes. Three primary end-of-life scenarios are typically considered for glulam buildings: (a) partial or complete reuse; (b) incineration, with or without energy recovery; and (c) landfilling [96,97,98]. These scenarios can occur in combination, each contributing to the overall carbon footprint based on their respective proportions. In this context, Darby et al. conducted a comparative assessment of glulam buildings under different end-of-life pathways, taking into account biogenic carbon dynamics [99]. Their findings, summarized in

Table 8. Phase-wise environmental impact values for different waste management strategies.

Phase	Reuse	Recycling	Incineration	Incineration (with Energy Recovery)	Landfill
Up to construction	−1100	−1100	−1100	−1100	−1100
Demolition	22	22	22	22	22
Transport	12	12	12	12	12
Re-manufacture	-	10	-	-	-
Re-transport	-	12	-	-	-
Re-construction	45	45	-	-	-
Combustion	-	-	1192	1192	-
Energy recovered	-	-	-	−628	-
Emissions from landfill	-	-	-	-	1013
Total	−1021	−99	126	−502	−53

, show that reuse and recycling offer the most environmentally advantageous outcomes. For example, Liang et al. reported that recycling mass timber at the end of its life provides a carbon offset of 364 kg CO₂eq/m², reducing greenhouse gas emissions by an additional 12% compared to reinforced concrete (RC) structures [100]. Beyond reducing global warming potential, such strategies promote a circular economy and support cradle-to-cradle approaches in construction. This not only enhances material efficiency but also contributes to long-term sustainability by extending the functional life of building components and reducing environmental burdens.

Studies conducted across various countries yield similar findings, as summarized in Table 3. However, the dominant approach to managing discarded wood components is their recycling into biofuel to replace fossil fuels, followed by landfilling. Improper incineration of wood, however, releases substantial greenhouse gases and harmful substances [101]. Head et al. highlighted that landfilling not only occupies land resources but also leads to methane emissions as wood decomposes anaerobically over time [102]. The effectiveness of reuse or recycling largely depends on the upstream production processes, construction methods, and the management of waste wood [25,103,104]. Current wood strength grading standards, such as EN 14081-1:2019, require detailed information on the wood species, growth region, and prior grading [105]. These requirements are often difficult to meet for recycled glulam, which impedes the realization of its full potential for reuse [106]. While wood recycling is practiced in demolition projects in Finland, a significant portion is shredded for biomass energy to offset demolition costs [107]. Wang et al. [108] found that 95% of renovation waste in nine cities across China is disposed of via landfilling. Similarly, in Brazil, over 10 million tons of wood waste are generated annually, with 63% being incinerated [48].

Despite these practices, the reuse of glulam remains underdeveloped, and its end-of-life management predominantly involves incineration or landfilling. In regions with more advanced glulam use, such as Sweden, recycling systems have been established. Harte et al. found that 90% of glulam beams were recycled during building demolitions in Sweden [109]. To promote the reuse and recycling of glulam, the In Future Wood Project was established, led by Sandberg et al. [110] and involving 22 partners from seven countries, including Finland and Germany. The project developed new design methods, assessed the performance of recycled wood products, and identified factors influencing demolition practices. Key recommendations included the preparation of demolition plans by designers, financial incentives from governments to encourage wood reuse, and the adoption of common standards and regulations. Furthermore, graded utilization of wood and the establishment of an integrated policy framework were recommended to support sustainable wood recycling and reuse practices.

5. Results and Discussion

This systematic review synthesized findings from 563 peer-reviewed studies published between 2014 and 2024 to comprehensively assess the sustainability performance of glulam (glued laminated timber) buildings using life cycle assessment (LCA) methodologies. The analysis covered diverse geographic contexts, material flows, and building typologies, with particular attention to regional carbon dynamics, life cycle emissions, circular economy integration, and socioeconomic implications.

• Regional Carbon Footprint Disparities: European and North American studies consistently reported lower cradle-to-gate and cradle-to-grave carbon footprints for glulam production, typically 28–70% lower than those of conventional concrete and steel structures. These outcomes were largely attributed to advanced forest certification schemes (e.g., PEFC, FSC), widespread use of renewable energy in production (e.g., biomass boilers, hydropower), and optimized logistic networks [65,67,78]. For instance, German and Swedish glulam production systems recorded embodied carbon intensities as low as 110–160 kgCO₂e/m². Conversely, studies from parts of Asia, Sub-Saharan Africa, and Latin America highlighted significant emission burdens due to unsustainable logging practices, reliance on coal and diesel-based electricity, and lack of infrastructure for energy-efficient manufacturing. Notably, Southeast Asia’s tropical hardwood glulam products showed embodied emissions up to 340 kgCO₂e/m² (despite high-carbon-storage potential), mainly due to illegal logging, inefficient processing, and long transportation distances [70,71].
• Life Cycle Performance: Comparative LCAs demonstrated that glulam buildings outperformed reinforced concrete and steel alternatives across 11 to 18 environmental impact categories, including global warming potential (GWP), acidification, eutrophication, smog formation, and fossil fuel depletion [3,88]. Glulam’s inherent carbon storage capacity contributed to offsets ranging from 30% to 47% of total life cycle emissions, depending on regional forest growth rates, product longevity, and structural mass per square meter. Moreover, integration of low-carbon energy systems (e.g., district heating, heat pumps, photovoltaic arrays) during the operational phase reduced GWP by 9% to 67%, particularly in cold-climate applications where heating energy dominates [91,93]. For example, a Swedish study showed net-negative GWP when glulam structures were paired with biomass-based integrated gasification combined cycle (BIGCC) systems.
• Circular Economy Benefits: End-of-life (EOL) strategies emerged as a key differentiator in sustainability outcomes. Recycling and reuse of glulam components reduced EOL emissions by 12% to 29% compared to conventional demolition and landfilling pathways [99,100]. Europe led in circularity, with Sweden reporting up to 90% recovery rates of glulam beams during demolition [109]. Prefabrication techniques, including cross-laminated and hybrid glulam systems, reduced on-site construction time by up to 48% and overall project costs by 10–15%, particularly in Central and Eastern European countries like Slovakia [80,81]. These strategies also minimized embodied construction emissions, often overlooked in conventional LCA models.
• Social and Economic Impacts: Glulam construction was associated with multiple co-benefits beyond environmental metrics. In the European Union, the mass timber sector supports over 1 million jobs, particularly in rural and forestry-dependent regions, contributing to regional economic resilience [90]. Studies in Japan, Austria, and Canada linked glulam interiors with improved indoor environmental quality (IEQ), including increased thermal comfort and reduced stress levels—up to a 15% decrease in occupant-reported stress compared to concrete interiors [94]. Furthermore, glulam’s relatively low weight reduced foundation loads and site impacts, expanding feasibility in both urban infill and remote locations.

These findings not only corroborate earlier assessments of glulam’s carbon sequestration and life cycle benefits, but also underscore persistent regional disparities. For example, while European case studies confirmed the long-term advantages of sustainably managed forests and integrated carbon accounting, tropical regions such as Indonesia and Brazil face leakage from illegal logging and post-harvest losses, which diminish net carbon storage gains over time [50]. Discrepancies also arose in operational phase evaluations: cold-climate buildings reported efficiency gains from high-performance envelope and HVAC integration, whereas in tropical zones, moisture resistance, termite control, and maintenance frequency were the dominant factors influencing long-term performance and emissions [7].

A notable gap identified across the reviewed literature is the limited availability of end-of-life data for glulam structures. Most of the current LCA studies rely on modeled assumptions, as relatively few glulam buildings constructed in the last two decades have reached their demolition phase. This calls for the development of dynamic predictive models and long-term monitoring systems to better estimate disposal pathways and material recovery rates [110]. Additionally, while the adoption of bio-based adhesives (e.g., lignin-phenol, soy protein) has been explored as a promising alternative to formaldehyde-based resins, scalability remains a challenge. Only 4% of studies reported successful industrial-scale substitution due to unresolved trade-offs between cost, mechanical performance, and durability under varying climate conditions [8]. This contrasts with more optimistic projections from early research and underscores the need for further innovation in sustainable bonding agents.

6. Conclusions

This review addressed three primary research objectives concerning the sustainability performance of glulam buildings across different life cycle stages and geographic contexts. Drawing from 563 peer-reviewed studies published between 2014 and 2024, our synthesis offers nuanced insights into the environmental, technical, and policy dimensions that influence glulam’s viability as a sustainable building material. Regarding the sustainability potential of glulam buildings, evidence overwhelmingly supports their effectiveness in reducing greenhouse gas (GHG) emissions throughout the entire life cycle. Emission reductions ranged from 28% to 70% compared to conventional materials such as reinforced concrete and steel. This is primarily attributed to glulam’s inherent carbon storage capacity, lower embodied energy, superior thermal insulation properties, and compatibility with energy-efficient building systems. Additional sustainability benefits were observed in construction speed and material circularity. Prefabricated glulam systems not only shortened construction timelines but also minimized on-site waste and energy use, reinforcing glulam’s alignment with low-impact construction practices. The carbon footprint profile of glulam buildings revealed substantial regional variability influenced by several interdependent factors. Forest management practices, the carbon intensity of regional energy grids, and the mode of material transport were among the most significant contributors to emission differences. Transportation emerged as a non-negligible component of embodied emissions, with aviation and road transport accounting for up to 24% of total GHGs in some cases. In contrast, waterborne shipping and localized production, especially in regions where forestry and manufacturing are co-located, significantly reduced transportation emissions. The use of prefabricated modules further amplified carbon savings by decreasing construction-related emissions and enabling better logistics. On the regional influences on glulam deployment, we identified major disparities driven by policy maturity, technological infrastructure, and forest governance. Europe and North America consistently demonstrated strong performance across all sustainability indicators, largely due to well-established regulatory frameworks (e.g., EPDs, timber traceability laws), financial incentives for green buildings, and access to certified forests. Meanwhile, regions such as Southeast Asia, Sub-Saharan Africa, and parts of Latin America face persistent barriers, including illegal logging, lack of investment in clean energy, and weak end-of-life wood management. The review underscores the importance of equitable international partnerships, harmonized grading and reuse standards (e.g., adaptations of EN 14081-1:2019), and capacity-building initiatives to address these structural gaps.

Based on these findings, we have several future research directions and policy recommendations, as follows:

• Advance bio-based adhesives: Current limitations in the scalability, performance, and cost-efficiency of bio-adhesives impede their adoption. Targeted R&D in lignin-, tannin-, or protein-based alternatives should be prioritized to reduce the fossil-derived chemical content in glulam.
• Develop region-specific LCAs:There is an urgent need for geographically contextualized LCA models that account for local climate, forestry practices, and construction typologies, particularly in underrepresented regions like Africa and South America.
• Enhance end-of-life data and predictive modeling: Many glulam buildings have yet to reach their end-of-life stage. Longitudinal studies and scenario-based modeling should be implemented to improve accuracy in LCA projections and support circular economy planning.
• Foster international collaboration and knowledge transfer: Partnerships such as the In Future Wood Project illustrate the importance of cross-border collaboration. Future efforts should expand shared databases, standardize life cycle inventory (LCI) formats, and facilitate policy learning between regions.
• Promote circular policy frameworks: Policymakers should incentivize material reuse, integrate cradle-to-cradle certification systems, and support demolition planning for material recovery. Financial tools such as green public procurement and carbon pricing should reward projects that demonstrate high material efficiency and low carbon intensity.